GB2307283A

GB2307283A - Rolling bearing seal

Info

Publication number: GB2307283A
Application number: GB9623561A
Authority: GB
Inventors: Eiichi Kobayashi; Yutaka Daikuhara
Original assignee: Minebea Co Ltd
Current assignee: Minebea Co Ltd
Priority date: 1995-11-20
Filing date: 1996-11-12
Publication date: 1997-05-21
Anticipated expiration: 2016-11-12
Also published as: GB9623561D0; JPH09144766A; US5957591A; GB2307283B; JP2917115B2; US6068407A; DE19646697C2; DE19646697A1

Abstract

The invention permits stacking of seals without possibility of the sticking of their synthetic rubber seal members to one another. Moreover, when assembling the seals to produce anti-friction bearings, the invention permits storing the seals as a stack in a stocker of an automatic assembler and, unlike the case of using silicon or like prior art anti-sticking material, substantially eliminates generation of fine particles or the like adversely affecting precision apparatuses and deteriorating the reliability thereof. In an anti-friction bearing comprising an inner ring (1), an outer ring (2), and rolling elements (3) provided between the inner and outer rings, a side gap between the inner and outer rings is closed by seals (4) of the invention, which each include a synthetic rubber seal member (6) and a surface active material (7) coated thereon.

Description

2307283 X- ANTI-FRICTION BEARING This invention relates to an antlfriction

bearing, in which seal. members are provided between inner and outer rings.

in an anti-friction bearing which comprises an inner ring, an outer ring and balls or like rolling elements provided between the inner and outer rings, seal members are provided between the inner and outer rings.

The seal members each comprise a metal core and a synthetic rubber member molded as a seal member on tht metal core surface. When assembling such seals to produce anti-frictional bearings, they arc s-tored in a staiked form in a stocker of an.automatic assembler.

The seals have to be supplied smoothly from the stocker to the automatic assembler. To prevent mutual sticking of the seals, the surface of the seal member molding of. synthetic rubber is coated with an anti-sticking agent, for instance an oil mainly composed of silicon.

When the prior art anti-friction bearing is used for journaling in a rotary part of a precision machine, fine

BAD ORIGINAL particles of the anti-sticking material are scattered in a gaseous form from. the seal member surface adverseiy affect other mechanisms in the. precision machine.

For example, where the bearing is used for a rotary 5 part of.a hard disc drive motor, fine anti-sticking agent particles ( of 1 A m and above) may become attached to the - surface or a magnetic disc, which is rotating at a high speed With only a small gap (of 1 pm and below) provided between it and a magnetic head. Therefore, the attached particles may collide with and cause damage to the magnetic head.

An object of the invention is to provide an anti friction bearing, which can eliminate damage to the components such as the magnetic head of a magnetic disc drive with which the bearing is used.

An anti-friction bearing according to the invention which comprises an inner ring, an outer ring, and roll;Lng elements provided between the inner and outer rings, t'"e side gap between the Inner and outer rings is closed by seals each including a synthetic rubber member and a surface active material coated thereon.

Suitably, the seals in the anti-triction bearing according to the invention, each include a synthetIc rubber molding formed on a metal core.

13AD ORIGINAL 3 An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:

- Fig. 1 is a front view showing an embodiment of an anti-friction bearing in accordance with the invention; Fig. 2 is a sectional view taken along line 11-11 in Fig. 1; and Fig. 3 is a perspective view of a seal used in an anti-friction bearing in accordance with the invention.

Figs. 1 and 2 show an anti-friction bearing comprising an inner ring 1, an outer ring 2, and balls 3 provided as rolling elements between the inner and outer rings 1 and 2.

Seals 4 each close the side gap between the inner and outer rings 1 and 2. Each seal 4 includes a ring-like metal core 5 and a synthetic rubber seal member 6 molded thereon. As shown in Fig. 3 a very BAD ORIGINAL thin surface active material layer 7 is formed as a surface active coating.

Ball retainers 8 are also provided By. using as the surface active material 7 a material which is mainly composed of fatty acid soap, the seal member surface can be made slippery to enhance the non-stick effect of the sealsin relation to one another and also to facilitate the assembling of the seals to produce the bearing.

The surface active material layer 7 as the surface 10. coating of the seal, may be formed by agitating an aqueous solution of the surf ace active material with the non-coated seal dipped therein Tor a predetermined period of time.

Alternatively, the aqueous solution of the surf ace activt material --may-be--spt-ayed 7CE1 t-be--nun--;coated seal, and dried.

Each seal 4 is assembled by fitting. the outer periphery 6a of the seal member 6 in a mounting groove 2a formed in. the outer ring 2 by adequately def orming the outer periphery 6a against the elastic restoring force thereof.

By so doing, the edge of the central opening 4a of the seal is faced on the outer periphery of a reduced diameter edge portion la of the inner ring 1. In this way, the side 5,,o ORIGIsAL 1 gap between the inner and outer rings Is seals 4.

closed by th c Undesired fine particles and gases, which are generated frour the surface of the seals 4 in the anti-friction bearing having tile above StrUcturCwere shown to be far below a prescribed level.

While in the above embodiment the surf ace active material was coated af ter the molding of the seal member, a surfaceactive =at erial which Is mainly composed of tatty acid soap may also serve as a releasing agent whien molding the seal member. in other this surface active material can facilitate the releasing in the molding process when it is coated beforehand.

An an:l-friction bearing having the above construction, provides the following functions and effects..

Since the surface active material coating does not adversely affect precis.ion apparatuses, instead of the prior art anti-sticking material mainly composed- of silicon, on the surface of the anti-friction bearing seal members, fine particles or the. like adversely affecting precision apparatuses and deteriorating the reliability thereof are hardly generated from the seals in the anti- t BAD ORGINAL 1 friction bearing according to the invention.

In add-i'k,-on, since the seals of the anti-friction bearing have the surface active material layer as their surfa ce coating, they can be stacked Without the Possibility of the:sticking of the synthetic rubber seal members to one another. Thus, when assembling them to produce antifriction bearings, they can be stored as a stack in a stocker of an automatic assembler and automatically assembled smoothly between the inner and outer rings.

BAD OFIAG 7

Claims

1. An anti-friction bearing comprising an inner ring (1), an outer ring (2), a plurality of rolling elements (3) provided between said inner and outer rings (1,2), and seals (4) located between said inner and outer rings, characterized in that said seals each include a seal member (6) made of synthetic rubber with a surface active material (7) coated thereon.

2. A bearing as claimed in claim 1, wherein said seals (4) each include a synthetic rubber molding (6) formed on a metal core (5).

3. A bearing as claimed in claim 1 or claim 2, wherein said rolling elements (3) are balls.

4. A bearing as claimed in any of claims 1 to 3, wherein the active material coating is formed substantially from fatty acid soap.